76 research outputs found

    A Highly Focused Antigen Receptor Repertoire Characterizes γδ T Cells That are Poised to Make IL-17 Rapidly in Naive Animals

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    Interleukin (IL)-17 plays a key role in immunity. In acute infections, a rapid IL-17 response must be induced without prior antigen exposure, and γδ T cells are the major initial IL-17 producers. In fact, some γδ T cells make IL-17 within hours after an immune challenge. These cells appear to acquire the ability to respond to IL-1 and IL-23 and to make IL-17 naturally in naïve animals. They are known as the natural Tγδ17 (nTγδ17) cells. The rapidity of the nTγδ17 response, and the apparent lack of explicit T cell receptor (TCR) engagement for its induction have led to the view that this is a cytokine (IL-1, IL-23)-mediated response. However, pharmacological inhibition or genetic defects in TCR signaling drastically reduce the nTγδ17 response and/or their presence. To better understand antigen recognition in this rapid IL-17 response, we analyzed the antigen receptor repertoire of IL-1R+/IL-23R+ γδ T cells, a proxy for nTγδ17 cells in naïve animals, using a barcode-enabled high throughput single-cell TCR sequence analysis. We found that regardless of their anatomical origin, these cells have a highly focused TCR repertoire. In particular, the TCR sequences have limited V gene combinations, little or no junctional diversity and much reduced or no N region diversity. In contrast, IL-23R- cells at mucosal sites similar to most of the splenic γδ T cells and small intestine epithelial γδ lymphocytes expressed diverse TCRs. This remarkable commonality and restricted repertoire of IL-1R+/IL-23R+ γδ T cells underscores the importance of antigen recognition in their establishment/function

    Study of Friction and Wear Effects in Aluminum Parts Manufactured via Single Point Incremental Forming Process Using Petroleum and Vegetable Oil-Based Lubricants

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    This paper focuses on studying how mineral oil, sunflower, soybean, and corn lubricants influence friction and wear effects during the manufacturing of aluminum parts via the single point incremental forming (SPIF) process. To identify how friction, surface roughness, and wear change during the SPIF of aluminum parts, Stribeck curves were plotted as a function of the SPIF process parameters such as vertical step size, wall angle, and tool tip semi-spherical diameter. Furthermore, lubricant effects on the surface of the formed parts are examined by energy dispersive spectroscopy (EDS) and scanning electron microscope (SEM) images, the Alicona optical 3D measurement system, and Fourier-transform infrared spectroscopy (FTIR). Results show that during the SPIF process of the metallic specimens, soybean and corn oils attained the highest friction, along forces, roughness, and wear values. Based on the surface roughness measurements, it can be observed that soybean oil produces the worst surface roughness finish in the direction perpendicular to the tool passes (Ra =1.45 μm) considering a vertical step size of 0.25 mm with a 5 mm tool tip diameter. These findings are confirmed through plotting SPIFed Stribeck curves for the soybean and corn oils that show small hydrodynamic span regime changes for an increasing sample step-size forming process. This article elucidates the effects caused by mineral and vegetable oils on the surface of aluminum parts produced as a function of Single Point Incremental Sheet Forming process parameters

    Enhanced ferromagnetism in CuO nanowires on the top of CuO nanograins.

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    In the past few years, a considerable effort has been devoted in order to grow magnetoelectric nanostructured materials. Besides fundamental science, they are very attractive in the electronic/spintronic industry as well as magnetic storage media, solar energy conversion due to their nanometer scale. It is believed that CuO is a magnetoelectric multiferroic system where a ferroelectric order is induced by the onset of a magnetic coupling at low temperatures. Furthermore, its simplest composition is the bases of cuprates which bring about the well-known high-temperature superconductivity. Bulk samples of CuO (which has an unpaired electron in the d-shell) show two antiferromagnetic phase transitions – a commensurate collinear state with the magnetic moments along the monoclinic b axis at TN ~ 213 K and an incommensurate spiral state with half of the magnetic moments in the ac plane at TN ~ 230 K

    Determination of Diagnostic Reference Levels (DRLs) in General Radiographyin Latin America

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    The International Atomic Energy Agency (IAEA) through the International Action Plan on Radiation Protection of Patients and the International Commission on Radiological Protection have for some time carried out important efforts to assure that in the medical applications of the ionising radiations, the optimisation of radiological protection of patients is fundamental, to such a point that the IAEA includes it directly as a requirement for these practices (in its International Basic Safety Standards for Protection against Ionising Radiation and for the Safety of Radiation Sources (BSS)-GSR Part 1, 2011). For this reason, among the objectives of Regional Project RLA/9/057 and Regional Project RLA/9/067, the intention was to establish the dose references in conventional radiology for Latin America, for the purposes of determining whether these doses comply with the requirements of the BSS and to tend to improve practices, in order to minimise the dose received by the patients.Fil: Blanco, Susana Alicia Ana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Belgrano. Facultad de Ingenieria; ArgentinaFil: Mora, Patricia. Centro de Investigación en Ciencias Atómicas, Nucleares y Moleculares; Costa RicaFil: Almonte, Narkiss. Comisión Nacional de Energía. Dirección Nuclear; República DominicanaFil: Benavente, Tony. Instituto Peruano de Energía Nuclear; PerúFil: Benson, Nadja. Ministerio de Salud. Dirección General de Salud; Reino UnidoFil: Blanco, Daniel. Universidad de la República. Centro de Investigaciones Nucleares; UruguayFil: Cárdenas, Juan. Centro de Protección e Higiene de las Radiaciones; CubaFil: Defaz Gómez, Yolanda. Hospital Oncológico SOLCA Nucleo de Quito; EcuadorFil: Edding, Oscar. Instituto de Salud Pública; ChileFil: Escobar, Carolina. Ministerio de Salud Pública y Acción Social. Unidad Reguladora de Radiaciones Ionizantes; El SalvadorFil: Fonseca, María. Hospital Nacional Roosevelt; GuatemalaFil: Gamarra, Mirta. Ministerio de Salud Pública y Bienestar Social; ParaguayFil: García Aguilar, Juan. Instituto Nacional de Investigaciones Nucleares; MéxicoFil: Khoury, Helen Jamil. Universidade Federal de Pernambuco; BrasilFil: Quintero, Ana Rosa. Hospital Oncológico "Dr Luis Razetti"; VenezuelaFil: Roas Zuniga, Norma. Universidad Nacional Autónoma de Nicaragua; NicaraguaFil: Zaire, Edgar. Instituto Boliviano de Ciencia y Tecnología Nuclear; BoliviaFil: Nader, Alejandro. International Atomic Energy Agency; Austri

    Insulin Induces Relaxation and Decreases Hydrogen Peroxide-Induced Vasoconstriction in Human Placental Vascular Bed in a Mechanism Mediated by Calcium-Activated Potassium Channels and L-Arginine/Nitric Oxide Pathways

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    Insulin induces relaxation in umbilical veins, increasing the expression of human amino acid transporter 1 (hCAT-1) and nitric oxide synthesis (NO) in human umbilical vein endothelial cells (HUVECs). Short-term effects of insulin on vasculature have been reported in healthy subjects and cell cultures; however, its mechanisms remain unknown. The aim of this study was to characterize the effect of acute incubation with insulin on the regulation of vascular tone of placental vasculature. HUVECs and chorionic vein rings were isolated from normal pregnancies. The effect of insulin on NO synthesis, L-arginine transport, and hCAT-1 abundance was measured in HUVECs. Isometric tension induced by U46619 (thromboxane A analog) or hydrogen peroxide (HO) were measured in vessels previously incubated 30 min with insulin and/or the following pharmacological inhibitors: tetraethylammonium (KCa channels), iberiotoxin (BKCa channels), genistein (tyrosine kinases), and wortmannin (phosphatidylinositol 3-kinase). Insulin increases L-arginine transport and NO synthesis in HUVECs. In the placenta, this hormone caused relaxation of the chorionic vein, and reduced perfusion pressure in placental cotyledons. In vessels pre-incubated with insulin, the constriction evoked by HO and U46619 was attenuated and the effect on HO-induced constriction was blocked with tetraethylammonium and iberiotoxin, but not with genistein, or wortmannin. Insulin rapidly dilates the placental vasculature through a mechanism involving activity of BKCa channels and L-arginine/NO pathway in endothelial cells. This phenomenon is related to quick increases of hCAT-1 abundance and higher capacity of endothelial cells to take up L-arginine and generate NO

    Investigación en matemáticas, economía y ciencias sociales

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    El resultado de este libro que reune inquietudes académicas en torno a temas tan estudiados como los que están alrededor del maíz, del frijol o del café; y tan contemporáneos como las aplicaciones concretas de las ciencias ya citadas, al estudio de la adopción del comercio electrónico en empresas del sector agroindustrial o, el caso de la generación de biogas o energía eléctrica por medio de biodigestores. Al editar este texto e incorporarlo a la bibliografía de los temas de referencia, se enriquecen opciones de consulta para los estudiosos de esos temas en general; pero también para interesados en aspectos tan específicos como la cadena de suministro del mercado hortofrutícola en Texcoco

    Multinational prospective cohort study of rates and risk factors for ventilator-associated pneumonia over 24 years in 42 countries of Asia, Africa, Eastern Europe, Latin America, and the Middle East: Findings of the International Nosocomial Infection Control Consortium (INICC)

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    Objective: Rates of ventilator-associated pneumonia (VAP) in low- and middle-income countries (LMIC) are several times above those of high-income countries. The objective of this study was to identify risk factors (RFs) for VAP cases in ICUs of LMICs. Design: Prospective cohort study. Setting: This study was conducted across 743 ICUs of 282 hospitals in 144 cities in 42 Asian, African, European, Latin American, and Middle Eastern countries. Participants: The study included patients admitted to ICUs across 24 years. Results: In total, 289,643 patients were followed during 1,951,405 patient days and acquired 8,236 VAPs. We analyzed 10 independent variables. Multiple logistic regression identified the following independent VAP RFs: male sex (adjusted odds ratio [aOR], 1.22; 95% confidence interval [CI], 1.16-1.28; P <.0001); longer length of stay (LOS), which increased the risk 7% per day (aOR, 1.07; 95% CI, 1.07-1.08; P <.0001); mechanical ventilation (MV) utilization ratio (aOR, 1.27; 95% CI, 1.23-1.31; P <.0001); continuous positive airway pressure (CPAP), which was associated with the highest risk (aOR, 13.38; 95% CI, 11.57-15.48; P <.0001)Revisión por pare

    Comunicación educación un campo de resistencias

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    El presente libro obedece a la imperiosa necesidad de desplegar la potencia de la Facultad de Ciencias de la Comunicación en la Corporación Universitaria Minuto de Dios -UNIMINUTO, de otras comunidades académicas y de los espacios de movimiento social interesados en deconstruir los discursos de comunicación y educación desde la perspectiva del pensamiento crítico. En este caso entendemos potencia como la fuerza individual y colectiva capaz de rebasar la racionalidad dominante en la sociedad contemporánea, colonizada por la economía como única mirada del mundo; esto es, potencia como ímpetu insospechado por el poder. Por otra parte, el libro tiene como eje articulador el concepto de resistencia, definido este como el acto de recrear la realidad a partir de las posibilidades que ofrece la comunicación, para generar producción de sentido y dinamizar el cambio social. Propone realizar el ejercicio de concebir el mundo desde una perspectiva diferente a la hegemónica y de crear multiplicidades que trabajen unidas, reconociendo sus diferencias pero vinculándose en un “lugar común” del cual, cada una de ellas, regrese a su lugar cotidiano transformada por la acción colectiva del campo de Comunicación - Educación

    Comunicación educación un campo de resistencias

    Get PDF
    El presente libro obedece a la imperiosa necesidad de desplegar la potencia de la Facultad de Ciencias de la Comunicación en la Corporación Universitaria Minuto de Dios -UNIMINUTO, de otras comunidades académicas y de los espacios de movimiento social interesados en deconstruir los discursos de comunicación y educación desde la perspectiva del pensamiento crítico. En este caso entendemos potencia como la fuerza individual y colectiva capaz de rebasar la racionalidad dominante en la sociedad contemporánea, colonizada por la economía como única mirada del mundo; esto es, potencia como ímpetu insospechado por el poder. Por otra parte, el libro tiene como eje articulador el concepto de resistencia, definido este como el acto de recrear la realidad a partir de las posibilidades que ofrece la comunicación, para generar producción de sentido y dinamizar el cambio social. Propone realizar el ejercicio de concebir el mundo desde una perspectiva diferente a la hegemónica y de crear multiplicidades que trabajen unidas, reconociendo sus diferencias pero vinculándose en un “lugar común” del cual, cada una de ellas, regrese a su lugar cotidiano transformada por la acción colectiva del campo de Comunicación - Educación
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